Physics – Condensed Matter – Statistical Mechanics
Scientific paper
2002-04-04
In: T. Poeschel and S. Luding (eds.), "Granular Gases", Lecture Notes in Physics Vol. 564, Springer (Berlin, 2000), p. 100
Physics
Condensed Matter
Statistical Mechanics
25 pages, 5 figures
Scientific paper
We consider collisional models for granular particles and analyze the conditions under which the restitution coefficient might be a constant. We show that these conditions are not consistent with known collision laws. From the generalization of the Hertz contact law for viscoelastic particles we obtain the coefficient of normal restitution \epsilon as a function of the normal component of the impact velocity v_{imp}. Using \epsilon(v_{imp}) we describe the time evolution of temperature and of the velocity distribution function of a granular gas in the homogeneous cooling regime, where the particles collide according to the viscoelastic law. We show that for the studied systems the simple scaling hypothesis for the velocity distribution function is violated, i.e. that its evolution is not determined only by the time dependence of the thermal velocity. We observe, that the deviation from the Maxwellian distribution, which we quantify by the value of the second coefficient of the Sonine polynomial expansion of the velocity distribution function, does not depend on time monotonously. At first stage of the evolution it increases on the mean-collision time-scale up to a maximum value and then decays to zero at the second stage, on the time scale corresponding to the evolution of the granular gas temperature. For granular gas in the homogeneous cooling regime we also evaluate the time-dependent self-diffusion coefficient of granular particles. We analyze the time dependence of the mean-square displacement and discuss its impact on clustering. Finally, we discuss the problem of the relevant internal time for the systems of interest.
Brilliantov Nikolai V.
Poeschel Thorsten
No associations
LandOfFree
Granular Gases with Impact-velocity Dependent Restitution Coefficient does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Granular Gases with Impact-velocity Dependent Restitution Coefficient, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Granular Gases with Impact-velocity Dependent Restitution Coefficient will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-640195